Complete the sum$-$of$-$the$-$years' digits method of depreciation.

$\backslash$table$[[\backslash$table$[[$Useful Life$],[($years$)]],\backslash$table$[[$Sum$-$of$-$the$-],[$Years$\text{'}]],$Depreciation Rate Fraction$],[$Year $1,$Year $3,$Year $5],[8,,,,]]$